TECHNICAL FIELD

[0001] This disclosure is generally directed to automated payment systems. More specifically, this disclosure is directed to a com discriminating apparatus with capacitive arrays.

BACKGROUND

[0002] Coin validation sometimes has a problem of coin clones or counterfeits, which are not recognizable with a traditionally used set of sensors. The sensors usually include magnetic (inductive), weight (mass) and geometrical (dimensions) sensors. However, for different coins, all of the above-mentioned types of sensors can produce the same results. Such coins can be made from the same material, have the same geometry parameters, and as a consequence, the same weight.

SUMMARY

[0003] This disclosure provides a coin discriminating apparatus with capacitive arrays.

[0004] An embodiment of this disclosure provides an apparatus for coin discriminating associated with differences in embossing patterns. The apparatus includes a coin guide with a path to receive and guide a com. The apparatus also includes a receiving electrodes arranged in a plane that is substantially parallel to a surface of the com. The apparatus also includes an excitation electrodes arranged in the plane. The apparatus also includes a signal generator configured to excite the excitation electrodes. The apparatus also includes a receiving circuit coupled to the receiving electrodes, the receiving circuit configured to detect the change in the capacitances between the receiving electrode and the coin.

[0005] Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

[0006] Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of this disclosure and its advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:

[0008] FIG. 1 A illustrates a coin discriminating apparatus with capacitive array sensors according to an embodiment of this disclosure;

[0009] FIG. I B illustrates a coin validator 110 according to one embodiment of the present disclosure;

[0010] FIG. 2A illustrates a schematic view of one electrode capacitive sensing element system according to an embodiment of this disclosure;

[0011] FIG. 2B illustrates schematics of an input circuit for a single electrode sensing element system according to an embodiment of this disclosure;

[0012] FIG. 3A illustrates a sectional view of a two electrode sensing element system according to an embodiment of this disclosure;

[0013] FIG. 3B illustrates schematics of an input circuit for a two electrode sensing element system according to an embodiment of this disclosure;

[0014] FIG. 4A illustrates a sectional view of a one-side capacitive array sensor electrode sensing element system and front view of the electrode sensing element system according to an embodiment of this disclosure;

[0015] FIG. 4B illustrates a block diagram of an input circuit for a high frequency switch according to an embodiment of this disclosure;

[0016] FIG. 4C illustrates schematics of an input circuit for a demodulator-amplifier circuit according to an embodiment of this disclosure; [0017] FIG. 5 illustrates a front view of linear array sensor with excitation electrodes on the same side of com guide as receiving electrodes according to an embodiment of this disclosure;

[ΘΘ18] FIG. 6A illustrates a front view of a linear capacitive array composed from two electrode sensing cells and using additional grounding eiectrodes according to an embodiment of this disclosure;

[0019] FIG. 6B illustrates schematic diagram of a high frequency commutator according to an embodiment of this disclosure;

[0020] FIG. 7 illustrates a front view of linear capacitive array with a common excitation electrode for all receiving electrodes and additional grounding electrodes according to an embodiment of this disclosure;

[0021] FIG. 8 illustrates a front view of an electrode system for a two-dimensional capacitive array that uses only receiving electrodes according to an embodiment of this disclosure;

[0022] FIG. 9 illustrates a front view of an electrode system for a two-dimensional capacitive array that uses common excitation electrodes for all receiving electrodes according to an embodiment of this disclosure;

[0023] FIG. 10 illustrates a front view of two-dimensional capacitive array that is composed from two electrode sensitive elements according to an embodiment of this disclosure;

[ΘΘ24] FIG. 1 1 illustrates an electrical block schematic of a driving module for arrays according to an embodiment of this discl osure; [0025] FIG. 12 illustrates a circuit diagram and outside connections for modules used for driving arrays shown on FIG. 8 and FIG,9 according to an embodiment of this disclosure; and

[0026] FIG. 13 illustrates a circuit diagram and outside connections for modules used for driving arrays shown on FIG. 10 according to an embodiment of this disclosure.

DET AILED DESCRIPTION

[0027] FIGURES 1 through 13, discussed below, and the various embodiments used to describe the principles of this disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of this disclosure may be implemented in any suitably arranged coin discriminating system.

[0028] The only feature that may be different between authentic and counterfeit coins or other coins is an embossed pattern. To differentiate between these coins, a validator may detect an embossed pattern or some special parameters of the pattern. Some solutions to this problem are targeted to using optic image sensors. But such approaches confront many difficulties, such as the lack of space inside a conventional coin validator results in using wide viewing angle cameras, adding mirrors for increasing distance to coin for maintaining a sensor in a small volume. One problem is illumination of a coin, which arises due to a mirror type of embossed coin surface. If the light illuminates coins at a particular angle, then reflected light from only some areas of coin surface could reach the camera lens. Alternatively, if fully diffused illumination is used, then it is difficult to receive a contrasting image. Additional problems can include old coins being oxidized or the surfaces start to reflect light in a diffused manner due to micro scraiches. All mentioned problems result in difficulties of optic variant realization. Determining embossing pattern heights is very diffi cult if an optic approach is used.

[0029] Other approaches in embossed pattern detection include using small inductances positioned close to coin surface or a magnetic sensor. A first disadvantage of using magnetic sensors is in possible resolution limit. When using surface mount inductors, this limit is determined by dimensions of each inductor itself plus necessary separation η distance on a printed circuit board (PCB). Rather big and expensive wounded inductors with resultant magnetic field perpendicular to PCB could be used in this variant. This results in approximately 3mm lower resolution limit. Practically the same result is for variant with spiral inductors formed by PCB technology. A second disadvantage is in choosing a high frequency limit. As far as it depends on such com material properties as magnetic permeability and conductivity, then it might appear to be too high for some coins. For coin embossing pattern detection, a capacitive approach with single measuring capacitor with full coin surface covering could also be used, but only one parameter characterizes the embossing pattern and a probability of the same results for different embossing patterns is high.

[0030] FIG. 1 A illustrates a coin discriminating apparatus 100 with capacitive array- sensors according to an embodiment of this disclosure. Coin discriminating apparatuses come in a wide variety of configurations, and FIG. 1 A does not limit the scope of this disclosure to any particular implementation of a com discriminating apparatus. Additionally, embodiments of this disclosure may be implemented in automatic ticket seller machines, gaming machine, automated payment machine, automatic teller machines, kiosks, and the like, and are not limited to use in only vending machines.

[0031] Coin 101 moves along coin guide between walls 102 and 103. In the coin guide walls 102 and 103, capacitive array assemblies 104 and 105 are mounted. In a different example embodiment, only one array, for example array 105, is used. In the longitudinal direction, the coin guide has some angle with horizontal direction and also the wall plane has a small angle with vertical direction. Such configuration results in rolling type motion of coin without wobbling and with sliding along one wall of com guide, without or with negligible sliding of lower coin edge. [0032] Capacitive sensing elements in capacitive arrays could be arranged in different configurations that could be divided in two main groups. The first group includes arrays which do not cover the whole coin surface. One example for such arrays is a linear array. The second group includes two dimensional arrays with capacitive elements arranged in plane with full coverage of coin surface. Example configurations for such arrays can be a square or rectangular type.

[0033] FIG. IB illustrates a com validator 110 according to one embodiment of the present disclosure. In one illustrative embodiment, coin validator 110 can include a coin discriminating apparatus 100. Additionally, embodiments of this disclosure may be implemented in automatic ticket seller machines, gaming machine, automated payment machine, automatic teller machines, kiosks, and the like, and are not limited to use in only vending machines.

[0034] Referring to FIG. I B, coin validator 110 comprises a coin recognition system 112, a coin separator 1 14 and a coin storage region 1 16. The coin validator 1 10 receives an inserted coin through an opening, which is connected to a payment access mechanism. The coin travels along a ramp in the coin validator 1 10 past sensors such as those shown at 125.

[0035] The sensors 125 generate electrical signals which are provided to a coin mechanism processor 130 such as a microprocessor or microcontroller. The electrical signals generated by the sensors 125 contain information corresponding to the measured characteristics of the coin, such as a coin's diameter, thickness, metal content, and electromagnetic properties. Based on these electrical signals, the coin mechanism processor 130 is able to discriminate whether the com is acceptable, and if so, the denomination of the coin. [0036] If [he coin is unacceptable, the com mechanism processor 130 controls a gate to direct the unacceptable coin to a reject chute. The reject chute is connected to the coin return, recess, in the alternative, acceptable coins are directed to the coin separator 114 by the gate. The coin separator 114 may have a number of gates arranged along a ramp and also controlled by signals from the coin mechanism processor 130, for diverting the coin from the ramp. The com may be diverted into respective containers, or the coin may be allowed to proceed along ramp to a path leading to a cash box (not shown).

[0001] Although FIGS. 1A-B illustrate examples of a com discriminating apparatus 100 and coin validator 110, various changes may be made to FIGS. 1 A-B. The coin discriminating apparatus 100 and com validator l lOcould be used in any device requiring coin validation, such as, but not limited to, automatic ticket seller machines, automatic teller machines, vending machines and other kiosks. Additionally, while this embodiment considers the use of a coin, additional types of negotiable instruments that evidences a right to the payment of a monetary obligation, typically issued by a central banking authority may be used such as any currency denomination, denomination of currency, valuable document, currency bill, bill, banknote, note, bank check, paper money, paper currency, coinage, and cash.

[0037] FIG. 2 A illustrates a schematic view of one electrode capacitive sensing element system 200 according to an embodiment of this disclosure. Electrode capacitive sensing element systems come in a wide variety of configurations, and FIG. 2A does not limit the scope of this disclosure to any particular implementation of an electrode capacitive sensing element system. The electrode capacitive sensing element system 200 could be used with coin discriminating apparatus 100 as shown in FIG. 1 A. [0038] In an example embodiment, sensor electrode 201 is positioned with some predetermined separation distance above a surface 210 of coin 202, Surface 210 can also be referred to as a face of coin 202. Surface 210 is not perfectly flat, but contains an embossed pattern. Any reference to a parallel plane of the surface of com 202 can be based on a plane created by an edge of surface 210 of coin 202 as shown in FIG. 2A. Similarly surface 211 of coin 202 includes an embossed partem.

[0039] In one or more embodiments, excitation electrodes 203 and 204 are also positioned in the same plane, which is parallel to plane surface created by an edge of surface 210 of coin 202. In another embodiment, the electrodes 203 and 204 can be arranged in a wedge shape or inclined with another surface. In yet another embodiment, excitation electrode 205 could be positioned on an opposite side of com guide from electrodes 203 and 204. All the excitation electrodes 203-205 are connected to signal generator 206. In one embodiment, a signal generator can be a high frequency generator. Recei ving electrode 201 is connected to receiving circuit 207 which has input capacitance Cm 209 and active input resistance R _m 208. Corresponding resistor R _m 208 and capacitor Cm 209 are shown inside receiving circuit 207.

[0040] FIG. 2B illustrates equivalent schematics of an input circuit 212 for a single electrode sensing element system according to an embodiment of this disclosure. Input circuits come in a wide vanety of configurations, and FIG. 2B does not limit the scope of this disclosure to any particular implementation.

[0041] In an example embodiment, capacitor CE-C 214 represents a capacitance between excitation electrodes and the com. Capacitor CC-R 216 represents a local capacitance between the com and receiving electrode. Q,. 218 and R _m 220 are respectively an input capacitance and input resistance of a receiving circuit. In one example embodiment, the excitation electrodes have a large area with respect to area of receiving electrode and are separated from the receiving electrode by a large distance. Such geometry results in high value of capacitance for capacitor C _E „c 214 with respect to a capacitance for capacitor CC-R 216. Also, such a configuration permits omitting direct capacitance coupling between an excitation electrode and generator electrodes. Capacitance for capacitor CC-R 216 can be dependent on the distance from the receiving electrode to the coin surface and can be sensitive to embossing pattern irregularities during coin motion.

[0042] In one example embodiment, the absolute value of capacitor CC-R 216 is rather small, and high frequencies must be used in this sensor. In one example embodiment, the system uses frequencies in the 80-150 MHz band. At such frequencies impedance of input capacitance C _in 218 is much lower than input resistance R _in 220 and this input resistance could be not taken into account. In this example, a signal from the generator 206 is transferred to the input of receiving circuit by a capacitive divider formed by capacitors CC-R 216 and C _in 218 without phase shift, where the CC-R 216 value varies with the local distance from the coin surface to the input electrode.

[0043] In another example, the capacitor may be replaced with an antenna. An antenna is a device which produces or receives travelling electromagnetic waves. In one example embodiment, an antenna can be used when a measuring distance is greater than at least one period of the electromagnetic wave. In this embodiment, when the measuring distance is less than one period, a capacitive approach can be used.

[0044] When using an antenna, the system may use frequencies of greater than 10 GHz. In different embodiments, other frequencies may work, such as frequencies within the 2-5GHz band. In further embodiments, frequencies within the 300-1000GHz band are used. For example, when there is a lmm measuring distance, the frequency of the electromagnetic wave can be near 300GHz. In different embodiments, any frequency in the microwave band can be used,

[0045] Although FIGS. 2A and 2B illustrate one example of an electrode capacitive sensing element system 200 with an input circuit 212, various changes may be made to FIGS. 2A and 2B. For example, a different input circuit can be used with the system 200. In different embodiments, the physical locations and size of the electrodes may be different.

[0046] FIG. 3A illustrates a sectional view of a two electrode sensing element system 300 according to an embodiment of this disclosure. Two electrode capacitive sensing element systems come in a wide variety of configurations, and FIG. 3A does not limit the scope of this disclosure to any particular implementation of a two electrode capacitive sensing element system. The two electrode capacitive sensing element system 300 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[0047] The system includes two local adjacent electrodes 301 and 302, where electrode 301 is used as an excitation electrode and electrode 302 is used as a receiving electrode. These two electrodes form an open type capacitor with an electric field that is spreading in the nearest vicinity of this electrode pair. Receiving electrode 302 is connected to receiving circuit 207 and generator electrode 301 is connected to output of generator 206. For maintaining coin 202 coupled to ground of electronic circuit GND, additional electrodes 303, 304 and 305 are used. In another embodiment, electrodes 303-305 are not used and surrounding PCB's and a chassis of the coin acceptor could perform a similar function.

[0048] FIG. 3B illustrates equivalent schematics of an input circuit for a two electrode sensing element system according to an embodiment of this disclosure. Input circuits come in a wide variety of configurations, and FIG. 3B does not limit the scope of this disclosure to any particular input circuit. [0049] In FIG. 3B, in an example embodiment, capacitor CG-C 314 is a capacitance between excitation electrode and coin, capacitor CC-GND 316 is a capacitance between the com and grounding electrodes 303-305; capacitor CG-R 318 is a direct capacitance between excitation electrode 301 and receiving electrode 302: capacitor CC-R 320 is capacitance between receiving electrode 302 and a coin, capacitor€ _½ 322 and resistor R _ir , 324 are input capacitance and input resistance of receiving circuit 207. In this example, there are three capacitances which are dependable on a local distance from the sensing capacitive element to the coin surface, capacitances CC-GND 316, CC-R 320 and CG-C 314. In an example embodiment, where the capacitance of CC-GND 316 is higher compared to capacitances for Cc_ R 320 and CG-C 314 capacitors, capacitor CG-C 314 may not have any impact on output signal. In an embodiment, a resultant transfer function from the generator to the receiving circuit will be dependent on capacitors CG-R 318 and CC-R 320 and will be sensitive to embossing pattern irregularities when the coin moves along the coin guide.

[0050] Although FIGS. 3A and 3B illustrate one example of a two electrode sensing element system 300 with an input circuit 312, various changes may be made to FIGS. 3A and 3B. For example, an input circuit described by different equivalent schematic can be used with the system 300. In different embodiments, the physical locations and size of the electrodes may be different.

[0051] FIG. 4A illustrates a sectional view of a one-side capacitive array sensor 405 and front view of the electrodes assembly 409 of an electrode sensing system 400 according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 4A does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 400 could be used with coin discriminating apparatus 100 as shown in FIG. 1. [0052] In an example embodiment, FIG. 4A shows a cross section of a coin 403 that is moving along a path 422 of a coin guide with walls 404 and 402. Capacitive array sensor 405 is mounted into or adjacent to wall 404. Array sensor 405 contains a set of receiving electrodes 406, shown in a side view 409A of a receiving electrodes assembly 409, arranged in a linear array across the coin guide. A front view 409B of the receiving electrodes assembly 409 is also shown FIG. 4A. Receiving electrodes 406 are separated from the com guide by a thin dielectric layer.

[0053] The output of high frequency signal generator 206 is connected to an excitation electrode 401. Generator 206 also has a reference output connected to a demodulator-amplifier circuit 408 (demodulator-amplifier can also be referred to as a receiving circuit). Each receiving electrode 406 is connected to a high frequency switch 407 that is driven by a processing device. In one example embodiment, the switch can be a commutator or a semiconductor switch. The operation of such an electrode system were described in descriptions of FIG. 2A and FIG. 2B. An output of the high frequency switch 407 is connected to demodulator-amplifier circuit 408, where a high frequency signal is demodulated and a received signal is amplified to a proper level for analog-digital converter (ADC) readings. Based on a successive connection of each receiving electrode and resulting readings, a linear instant image is received. The image can be used to i dentify an embossing pattern of the coin 403.

[0054] FIG. 4B illustrates a block diagram of an input circuit 440 for a high frequency switch according to an embodiment of this disclosure. In one example embodiment, the high frequency switch can be switch 407 shown on FIG. 4A. Input circuits come in a wide variety of configurations, and FIG. 4B does not limit the scope of this disclosure to any particular implementation of input circuit. The input circuit 440 could he used with electrode sensing system 400 as shown in FIG. 4A.

[0055] In one embodiment, FIG. 4B contains a driving assembly 410 that includes registers or decoders and is driven by an external processing device. The driving assembly 410 is configured to switch one of the modules 411 into an active state. Each module 411a-n includes input/outputs 1-3. Each electrode 406 is served by an individual module of the same type as modules 411. Each module contains a buffer amplifier 412 with high input and low output impedances. An output of a buffer amplifier is connected to high frequency switch 413, driven by a corresponding output of a driving assembly 410 at input 2. In one example embodiment, all outputs of the modules 411a-n are coupled together. Such an arrangement is capable of successively connecting each receiving electrode to an input of demodulator- amplifier.

[0056] FIG. 4C illustrates block diagram of a demodulator-amplifier circuit 408 according to an embodiment of this disclosure. Demodulator-amplifiers come in a wide variety of configurations, and FIG. 4C does not limit the scope of this di sclosure to any particular implementation of demodulator-amplifier. The demodulator-amplifier 420 could be used with electrode sensing system 400 as shown in FIG. 4A.

[0057] In one example embodiment, demodulator 414 can be a mixer, such as a frequency mixer. In one example, the demodulator 414 is a double balance mixer with differential inputs and differential outputs. In other embodiments, the demodulator 414 can be a single balanced mixer, unbalanced mixer, etc. A reference high frequency voltage from a generator can also be used with demodulator 414 for compensation of initial alternating current (AC) voltage on an "input" of the demodulator 414. [0058] A compensation voltage is formed by a capacitive divider formed by capacitors 415 and 416, A differential output of the demodulator 414 is connected to subtraction amplifier 417. A received single ended signal from amplifier 417 is amplified by amplifier 418. An output from an external digital to analog converter (DAC) is used for maintaining amplifier 418m a desired state.

[0059] Although FIGS. 4 A and 4C illustrate an example electrode sensing system 400, various changes may be made to FIGS. 4 A and 4C. For example, different demodulator- amplifier circuits can be used with the system 400. In different embodiments, the physical locations and size of the electrodes may be different.

[0060] FIG. 5 illustrates a front view of linear array sensor 501 with excitation electrodes 503 and 504 on the same side of coin guide as receiving electrodes of an electrode sensing system 500 according to an embodiment of this disclosure according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 5 does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 500 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[0061] In one example embodiment, linear array sensor 501 is implemented into multilayer printed circuit board (PCB). Each receiving electrode 502 could have different forms. For example, in one embodiment, a disk type of electrode is used to achieve axial symmetry.

[0062] In this example, excitation electrodes 503 and 504 are positioned on both sides of linear array and are separated from receiving electrodes 502 by a rather large distance. Such an arrangement makes direct capacitive coupling between excitation and receiving electrodes sufficiently small. Dimensions of these excitation electrodes 503 and 504 can be chosen such thai, while coin 505 is passing along receiving electrodes 502, a threshold amount of a surface of coin 505 is covered by excitation electrodes 502. As used herein, "covered" is defined to indicate the portion of coin 505 that the excitation electrodes 503 and 504 are able to affect to achieve a desired result. In this example, capacitances between the coin 505 and excitation electrodes 503 and 504 can be high and can induce proper AC voltage on the com 505. All of the electrodes 502-504 can be separated from the com 505 by a thin dielectric layer.

[0063] Linear array sensor 501 could be used with additional excitation electrodes positioned on an opposite side of the coin guide as the sensor 405 was for the example illustrated in FIG. 4A. All excitation electrodes 503 and 504 can be connected to a high frequency signal generator 206. Receiving electrodes 502 can be connected to a receiving assembly with the same structure as used for the example illustrated in FIG. 4A with a high frequency switch 407 and demodulator-amplifier circuit 408.

[ΘΘ64] Although FIG. 5 illustrates an example electrode sensing system 500, various changes may be made to FIG. 5. For example, different receiving circuits can be used with the system 500. In different embodiments, the physical locations and size of the electrodes may be different.

[ΘΘ65] FIG. 6A illustrates a front view of a linear capacitive array 601 in an electrode sensing system 600 including two electrode sensing cells 602 and 603 and using additional grounding electrodes 604 and 605 according to an embodiment of this disclosure. Electrode sensing systems 600 come in a wide variety of configurations, and FIG. 6A does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 600 could be used with coin discriminating apparatus 100 as shown m FIG. 1. [0066] In one example embodiment, array 601 contains each sensitive element composed from two electrodes, receiving electrode 602 and excitation electrode 603. The geometry of these electrodes could be different but one or more embodiments can include an axial symmetry as shown in FIG. 6A. In other embodiments, non-axial symmetry can be used.

[0067] Operations using linear capacitive array 601 can include the activation of only one pair of electrodes during measuring. A "pair" of electrodes as used in this example includes a receiving electrode 602 and an excitation electrode 603.

[0068] In this example, penetration of signals from inactive elements above the coin 606 can be negligible. In one embodiment, for activation of excitation electrodes from generator 206, a high frequency switch 607 can be used.

[0069] In another embodiment, the coin 606 is maintained at ground potential. For this example, additional electrodes 604 and 605 are connected to ground. Coupling the coin 606 to ground could be achieved by using a grounded electrode incorporated into an opposite wall of a coin guide. A receiving assembly for this example can be the same as for the examples illustrated in FIG. 4A and FIG. 5, with high frequency switch 407 and demodulator-amplifier circuit 408.

[0070] FIG. 6B illustrates a block diagram of commutator circuit 612 for a driving assembly 410 according to an embodiment of this disclosure. Commutator circuits come in a wide variety of configurations, and FIG. 6B does not limit the scope of this disclosure to any particular implementation of commutator circuit. ^' The commutator circuit 612 could be used with electrode sensing system 600 as shown in FIG. 6A.

[ΘΘ71] In one embodiment, FIG. 6B contains a driving assembly 410 that includes registers or decoders and is driven by an external processing device. An internal structure of high frequency switches 608a-n is shown. The driving assembly 410 is configured to switch one of the modules 608 into an active state. Each module 608a-n includes input/outputs 1 -3. High frequency switch 610, used in module 608, could be of a different type than in input switch 407 of FIG. 4B due to switching signals with high amplitude level. Each output of switches is connected to corresponding excitation electrode and all inputs of the switch 610 are connected to a generators output. Different examples of electrode sensing system 600 shown in FIG. 6A can localize high frequency circuits in order to dimmish radio emissions.

[0072] Although FIGS. 6A and 6B illustrate an example electrode sensing system 600, various changes may be made to FIGS. 6A and 6B. For example, different input circuits can be used with the system 600. In different embodiments, the physical locations and size of the electrodes may be different.

[0073] FIG. 7 illustrates a front view of linear capacitive array 701 with a common excitation electrode 703 for all receiving electrodes 702 and additional grounding electrodes 704 and 705 of an electrode sensing system 700 according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 7 does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 700 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[ΘΘ74] In FIG. 7, an example is shown for a low recognition sensor while maintaining a coin at a ground potential. Linear capacitive array 701 contains a set of receiving electrodes 702, which are surrounded by common excitation electrode 703. In one embodiment, the array 701 includes additional grounded electrodes 704 and 705,

[ΘΘ75] Common excitation electrode 703 can be directly connected to an output of generator 206. Due to a large surface of additional ground electrodes with respect to total surface of excitation electrodes, high frequency voltage of com 706 can be negligible, A receiving assembly in FIG. 7 can be similar to the examples illustrated in FIG. 4A, FIG. 5 and FIG. 6A with a high frequency switch 407 and demodulator- amplifier circuit 408.

[0076] Although FIG. 7 illustrates an example electrode sensing system 700, various changes may be made to FIG. 7. For example, different input circuits can be used with the system 700. In different embodiments, the physical locations and size of the electrodes may bedifferent.

[0077] Depending on a type of coin acceptor, coin motion could be different. The movement of the coin can be translation movement or combined translation with rotation. If there is rotation combined with arbitrary sliding, two-dimensional arrays can provide reproducible two-dimensional pattern of coin surface. Capacitive sensitive elements in two- dimensional arrays could be arranged in different shapes. Example shapes can include square or rectangular types of arrangement with full covering of possible coin surface.

[0078] FIG. 8 illustrates a front view of an electrode system 800 for a two- dimensional capacitive array 80 ! that uses only receiving electrodes 802 according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 8 does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 800 could be used with com discriminating apparatus 100 as shown in FIG. 1.

[0079] In FIG. 8, a front view is shown of an example of a two-dimensional array

801. This example contains only receiving electrodes 802. In one example embodiment, such capacitive arrays need an AC voltage on testing coin. A coin excitation could be realized by a coin capacitive coupling with additional excitation electrodes mounted in an opposite side of the com guide. [0080] Although FIG. 8 illustrates an example electrode sensing system 500, various changes may be made to FIG. 8. For example, different receiving circuits can be used with the system 800. In different embodiments, the physical locations and size of the electrodes may be different.

[0081] FIG. 9 illustrates a front view of an electrode system 900 for a two- dimensional capacitive array 901 that uses common excitation electrodes 902 for all receiving electrodes 903 according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 9 does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode sensing system 900 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[0082] In FIG. 9, an example is shown of two-dimensional capacitive array 901. This example contains a set of receiving electrodes 903 and common excitation electrode 902, which surrounds all the receiving electrodes of array. In this example, the common excitation electrode is directly connected to the output of the high frequency signal generator.

[0083] Although FIG. 9 illustrates an example electrode system 900, various changes may be made to FIG. 9. For example, different receiving circuits can be used with the system 900. In different embodiments, the physical locations and size of the electrodes may be different.

[ΘΘ84] FIG. 10 illustrates a front view of an electrode system 1000 for two- dimensional capacitive array 1001 that is composed from two electrode sensing elements 1002 and 1003 according to an embodiment of this disclosure. Electrode sensing systems come in a wide variety of configurations, and FIG. 10 does not limit the scope of this disclosure to any particular implementation of an electrode sensing system. The electrode system 1000 could be used with com discriminating apparatus 100 as shown in FIG. 1. [0085] In FIG. 10, an example is shown of a two-dimensional capacitive array 1001. Each capacitive sensing element in this array contains individual excitation electrode 1003, which is adjacent with receiving electrode 1002. In one embodiment, control of capacitive arrays shown on FIG. 8, FIG. 9 and FIG. 10 can assume successive activation of each capacitive element of array. In an embodiment, it is inadmissible to electrically couple or simultaneously activate any group of receiving electrodes. In an example of electrically coupling or simultaneously activating of receiving electrodes group, result can be dependent on some average value of local embossing pattern distances to all of these electrodes.

[0086] Although FIG. 10 illustrates an example electrode system 1000, various changes may be made to FIG. 10. For example, different receiving circuits can be used with the system 1000. In different embodiments, the physical locations and size of the electrodes may be different.

[0087] FIG. 11 illustrates an electrical block schematic of an activation circuit 1100 for arrays according to an embodiment of this disclosure. In different embodiment, the circuit 1 100 can be used in arrays shown on FIG. 8, FIG. 9 and FIG. 10. Activation circuits come in a wide variety of configurations, and FIG. 1 1 does not limit the scope of this disclosure to any particular implementation of an activation circuit. The activation circuit 1 100 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[0088] In FIG. 11, each capacitive element as shown in FIGS. 8-10 is driven by individual module 1102. Each module 1102 is marked by "M" and could be different for different types of arrays. Each module 1 102 has two activation digital inputs and becomes active at proper combination of signals on these digital inputs. Module array 1101 is driven by two sets of registers or decoders of the driving assembly 410, marked by "R" 1 106 and "C" 1108. Outputs of these "R" 1106 and "C ^" 1108 circuits are arranged in rows and columns. Each module "M" 1102 is connected to corresponding intersecting row lines 1104 and column lines 1 103. One input is connected to corresponding row line 1104 and one input is connected to corresponding column line 1 103. By choosing an active set of input signals on a particular column line 1103 and a particular row line 1104, a corresponding module 1102 is activated.

[0089] Although FIG. 11 illustrates one example of an activation circuit 1100, various changes may be made to FIG. 11. For example, different sets of registers or decoders of the driving assembly 410 can be used.

[0090] FIG. 12 illustrates a circuit diagram 1200 and outside connections for modules used for driving arrays according to an embodiment of this disclosure. Circuits come in a wide variety of configurations, and FIG. 12 does not limit the scope of this disclosure to any particular implementation of a circuit. The circuit 1200 could be used with coin discriminating apparatus 100 as shown in FIG. 1. In different example embodiments, the circuit diagram 1200 can be used for driving arrays as shown in FIG. 8 and FIG. 9.

[0091] In FIG. 12, an example embodiment of a module M is shown marked as "Ml ," 1210 which in different embodiments, is able to serve capacitive arrays 801 and 901, respectively shown on FIG. 8 and FIG. 9. Module 1210 includes an AND logic element 1201, a linear buffer repeater 1202, and a high frequency switch 1203.

[0092] In one embodiment, digital inputs 3 and 4 are inputs of an AND logic element

1201, which drives high frequency switch 1203. input 3 is connected to corresponding row line and Input 4 is connected to corresponding column line. Module 1210 includes linear buffer repeater 1202 with high input impedance, the output of which is connected to a high frequency switch. Receiving electrode 1204 is connected to high impedance input of repeater

1202. Outputs of all array modules of Ml type can be connected to common load resistor 1205. A high frequency signal from resistor 1205 is connected to input of demodulator - amplifier circuit 408 through capacitor 1206.

[0093] Although FIG. 12 illustrates one example of a circuit diagram 1200, various changes may be made to FIG. 12. For example, a different arrangement of components in the module can be used. In various embodiments, number of inputs and outputs may be different.

[0094] FIG. 13 illustrates a circuit diagram 1300 and outside connections for modules used for driving arrays according to an embodiment of this disclosure. Circuits come in a wide variety of configurations, and FIG. 13 does not limit the scope of this disclosure to any particular implementation of a circuit. The circuit 1300 could be used with coin discriminating apparatus 100 as shown in FIG. 1.

[0095] In FIG. 13, an example embodiment of a module M is shown marked as "M2" 1310. In one example embodiment, the module 1310 is able to drive elements of capacitive array shown on FIG. 10. The module 1310 can include linear buffer 1301, high frequency switch 1302, AND logic element 1305. Additional elements in module 1310 include a high frequency switch 1303 for generator signal output and a load resistor 1304.

[0096] High frequency switch 1303 is driven by AND logic element 1305 which drives high frequency switch 1302, Because of this arrangement, switches 1302 and 1303 become active simultaneously. An input of high frequency switch 1302 is connected to single generator 206. All outputs of module 1310 are connected to common load resistor 1308. A high frequency signal from this common load resistor 1308 is connected to an input of demodulator-amplifier circuit 408 through capacitor 1309.

[0097] Although FIG. 13 illustrates one example of a circuit diagram 1300, various changes may be made to FIG. 13. For example, a different arrangement of components in the module can be used. In various embodiments, number of inputs and outputs may be different. [0098] One example embodiment can include a coin discriminating apparatus for coin discriminating by differences in embossing patterns, comprising: a plurality of receiving electrodes arranged in plane parallel to face surface of a coin; excitation electrode(s) positioned in plane(s) parallel to face surface of a coin: high frequency excitation means for excitation of excitation electrodes; capacitance measuring means for detecting changes in capacitances between electrodes and coin caused by variations in distances from electrodes to coin surface due to embossed pattern irregularities; and high frequency switches for successive measuring of capacitances for each receiving electrode of array with respect to coin using single capacitance measuring electronic circuit.

[0099] In one or more above examples, the plurality of receiving electrodes are arranged in array that does not cover the entire coin surface, wherein the electrodes are positioned across com guide and separated from coin surface by a thin dielectric substrate.

[0100] In one or more above examples, the plurality of receiving electrodes are arranged in two dimensional array, which covers the entire coin surface and is separated from coin surface by thin dielectric substrate.

[0101] In one or more above examples, the excitation electrodes are capacitively coupled to the coin and excite a high frequency voltage on the coin without direct excitation of receiving electrodes.

[0102] In one or more above examples, the excitation electrodes are positioned on the same side of coin guide where the receiving electrodes are positioned.

[0103] In one or more above examples, the excitation electrodes are positioned on an opposite side of coin guide with respect to a side where the receiving electrodes are positioned. [0104] In one or more above examples, the excitation electrodes are positioned on both sides of coin guide.

[0105] In one or more above examples, the excitation electrodes are positioned in pairs with the receiving electrodes forming a plurality of capacitors where the receiving electrodes are capacitively coupled to the com.

[0106] In one or more above examples, the capacitors have both excitation and receiving electrodes capacitively coupled to the coin.

[0107] In one or more above examples, all excitation electrodes are connected together forming a single excitation electrode that has capacitive coupling with all receiving electrodes.

[0108] In one or more above examples, the additional electrodes, connected to ground, are used to maintain the com being coupled to the ground by a capacitance between the additional electrodes and the coin.

[0109] In one or more above examples, the additional high frequency switches of the excitation electrodes are used together with high frequency switches of receiving electrodes for successive activating of each pair of receiving and excitation electrodes.

[0110] In one or more above examples, the only receiving electrode is capacitively coupled to the coin and the excitation electrode is separated from the coin surface and excites high frequency voltage on the receiving electrode by capacitive coupling with circuit, connected to the receiving electrode.

[0111] In one or more above examples, the two independent capacitive arrays with independent electronic circuits are positioned on both sides of the coin guide for scanning of both face sides of the coin. [0112] In one or more above examples, the two independent capacitive arrays are of the same type with the same geometrical configuration of electrodes,

[0113] In one or more above examples, the two independent capacitive arrays are of different types with different sizes and numbers of receiving and excitation electrodes in arrays on opposite walls of the coin guide, forming two arrays with different resolutions.

[0114] In one or more above examples, the capacitive array has two electrode systems driven by common electronic circuit which are positioned on both sides of coin guide for scanning of both face sides of coin.

[0115] In one or more above examples, the two electrode systems are of the same type with the same geometrical configuration of electrodes.

[0116] In one or more above examples, the two electrode systems are of different types with different sizes and numbers of receiving and excitation electrodes in electrode systems on opposite walls of com guide, forming two electrode systems with different resolutions.

[0117] In one or more of the above examples, figures, and embodiments, the capacitor may be replaced with an antenna. An antenna is a device which produces or receives travelling electromagnetic waves. In one example embodiment, an antenna can be used when a measuring distance is greater than at least one period of the electromagnetic wave. In this embodiment, when the measuring distance is less than one period, a capacitive approach can be used.

[0118] When using an antenna, the system may use frequencies of greater than 10 GHz. In different embodiments, other frequencies may work, such as frequencies within the 2-5GHz band. In further embodiments, frequencies within the 300-1000GHz band are used. For example, when there is a 1mm measuring distance, the frequency of the electromagnetic wave can be near 300GHz. In different embodiments, any frequency in the microwave band can be used.

[0119] In some embodiments, various functions described in this patent document are implemented or supported by a computer program.

[0120] An example embodiment provides an apparatus for coin discriminating associated with differences in embossing patterns, comprising: a coin guide including a path to receive and guide a coin; one or more receiving electrodes arranged in a plane that is substantially parallel to a surface of the coin; one or more excitation electrodes arranged in the plane; a signal generator configured to excite the one or more excitation electrodes; and a receiving circuit coupled to the one or more receiving electrodes, the receiving circuit configured to detect the change in the capacitance between the one or more receiving electrodes and the coin.

[0121] In one or more of the above examples, the change in capacitances is caused by variations in distances between the one or more receiving electrodes and the surface of the coin due to embossed pattern irregularities.

[0122] In one or more of the above examples, the apparatus further comprises at least one switch configured to activate a receiving electrode of the one or more receiving electrodes, wherein each of the at least one switch is coupled to each of the one or more receiving electrodes.

[0123] In one or more of the above examples, the one or more receiving electrodes comprise multiple receiving electrodes arranged substantially linearly, such that the multiple receiving electrodes do not cover an entirety of the surface of the coin, wherein the multiple receiving electrodes are separated from the surface of the coin by a dielectric substrate. [0124] In one or more of the above examples, the one or more receiving electrodes comprise multiple receiving electrodes arranged in a two-dimensional array, the two- dimensional array substantially covering an entirety of the surface of the coin, wherein the two-dimensional array is separated from the surface of the coin by a dielectric substrate.

[0125] In one or more of the above examples, the one or more excitation electrodes are capacitively coupled to the com, wherein the one or more excitation electrodes excites a high frequency voltage on the coin without direct excitation of the one or more receiving electrodes.

[0126] In one or more of the above examples, the one or more excitation electrodes are positioned on a same side of the coin as the one or more recei ving electrodes.

[0127] In one or more of the above examples, the one or more excitation electrodes are positioned on an opposite side of the path of coin guide as the one or more receiving electrodes.

[Θ128] In one or more of the above examples, multiple excitation electrodes are used, and the excitation electrodes of the multiple excitation electrodes are positioned on opposite sides of the path of coin guide, respectively.

[0129] In one or more of the above examples, each of the one or more excitation electrodes are positioned in a pair with one of the one or more receiving electrodes, wherein each of the one or more receiving electrodes forms part of a capacitor where each of the one or more receiving electrodes is capacitively coupled to the com.

[0130] In one or more of the above examples, the capacitor includes the excitation electrode and the receiving electrode capacitively coupled to the com.

[0131] In one or more of the above examples, the one or more excitation electrodes comprises multiple excitation electrodes and the one or more receiving electrodes comprise multiple receiving electrodes, and wherein all of the multiple excitation electrodes are connected together forming a single excitation electrode that is capacitively coupled with all of the multiple receiving electrodes.

[0132] In one or more of the above examples, the apparatus further includes grounded electrodes, connected to ground, coupling the coin to ground by a capacitance between the grounded electrodes and the coin.

[0133] In one or more of the above examples, the one or more excitation electrodes are coupled to one or more high frequency switches and the one or more receiving electrodes are coupled to another high frequency switch to s uccessively activate of the pair.

[0134] In one or more of the above examples, the excitation electrode of the pair is configured to excite a high frequency voltage on the receiving electrode of the pair by capacitively coupling with the receiving circuit, connected to the receiving electrode.

[0135] In one or more of the above examples, the apparatus further includes a first array comprising the one or more receiving electrodes, the one or more excitation electrodes, and the receiving circuit; and a second array comprising a second one or more receiving electrodes, a second one or more excitation electrodes, and a second receiving circuit, wherein the receiving circuit is independent from the second receiving circuit, and wherein the first array and second array are positioned on opposite sides of the path of the coin guide.

[0136] In one or more of the above examples, the first array and second array include a same geometrical configuration of receiving and excitation electrodes.

[0137] In one or more of the above examples, the first array and second array have different sizes of receiving and excitation electrodes or different numbers of receiving and excitation electrodes. [0138] In one or more of the above examples, the apparatus further includes a first array comprising the one or more receiving electrodes, the one or more excitation electrodes, and the receiving circuit; and a second array comprising a second one or more receiving electrodes, a second one or more excitation electrodes, wherein the receiving circuit is coupled to the second one or more receiving electrodes and the second one or more excitation electrodes, and wherein the first array and second array are positioned on opposite sides of the path of the coin guide.

[0139] In one or more of the above examples, the first array and second array include a same geometrical configuration of receiving and excitation electrodes.

[0140] In one or more of the above examples, the first array and second array include one or more of different sizes of receiving and excitation electrodes or different numbers of receiving and excitation electrodes.

[0141] In one or more of the above examples, each of the one or more excitation electrodes are positioned in a pair with one of the one or more receiving electrodes, wherein each of the one or more receiving electrodes forms part of an antenna.

[0142] It may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term "communicate," as well as derivatives thereof, encompasses both direct and indirect communication. The terms "include" and "comprise," as well as derivatives thereof, mean inclusion without limitation. The term "or" is inclusive, meaning and/or. The phrase "associated with," as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The phrase "at least one of," when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, "at least one of: A, B, and C" includes any of the following combinations: A, B, C, "A and B", "A and C", "B and C", and "A and B and C",

[0143] The description in the present application should not be read as implying that any particular element, step, or function is an essential or critical element that must be included in the claim scope. The scope of patented subject matter is defined only by the allowed claims. Moreover, none of the claims invokes 35 U.S.C. § 112(f) with respect to any of the appended claims or claim elements unless the exact words "means for ^" ' or "step for" are explicitly used in the particular claim, followed by a participle phrase identifying a function. Use of terms such as (but not limited to) "mechanism," "module," "device," "unit," "component," "element," "member," "apparatus," "machine," "system," "processor," or "controller" within a claim is understood and intended to refer to structures known to those skilled in the relevant ait, as further modified or enhanced by the features of the claims themselves, and is not intended to invoke 35 U.S.C. § 112(f).

[0144] While this disclosure has described certain embodiments and generally associated methods, alterations and permutations of these embodiments and methods will be apparent to those skilled in the art. Accordingly, the above description of example embodiments does not define or constrain this disclosure. Other changes, substitutions, and alterations are also possible without departing from the spirit and scope of this disclosure, as defined by the following claims.